Mycobacterium tuberculosis antigens (Mtb antigens) (Mtb antigens)

Mycobacterium tuberculosis (Mtb) antigens are a diverse array of proteins and lipids that are essential for the survival, virulence, and host-interaction of the TB bacterium (Groschel et al., 2016). These antigens, including the well-characterized ESAT-6 (6 kDa early secretory antigenic target) and CFP-10 (culture filtrate protein 10), are secreted by the bacterium to modulate host immune responses and facilitate phagosomal escape (Andersen & Kaufmann, 2014). As immune targets, these molecules are the foundation for diagnostic assays like the Interferon-Gamma Release Assay (IGRA) and are the primary components of modern subunit vaccines (Pai et al., 2016). Therapeutic intervention focuses on using these antigens to stimulate a Th1-polarized cellular immune response, characterized by the activation of CD4+ and CD8+ T cells that produce protective cytokines such as IFN-gamma and TNF-alpha (Lienhardt et al., 2016). While the BCG vaccine is the only currently approved immunization, it lacks consistent efficacy in adults, leading to the development of candidates like M72/AS01E and H56:IC31 which target specific Mtb antigen combinations (WHO, 2023). These antigens are critical for both preventing infection and managing latent tuberculosis by maintaining a robust immune surveillance state.

Other names

M. tuberculosis proteinsTB antigensMycobacterial antigensT-cell antigens of Mtb

The mechanism involves the presentation of mycobacterial peptides by MHC class I and II molecules to T-lymphocytes, triggering the release of Th1 cytokines (IFN-gamma, TNF-alpha) that activate macrophages to kill intracellular M. tuberculosis (Andersen & Kaufmann, 2014). Vaccines utilizing these antigens aim to establish a memory T-cell population that can rapidly respond upon subsequent exposure to the pathogen (Groschel et al., 2016).